Construction or preparation of road-surfaces and pavements.



'KARL'LUDWIG VALENTIN ZIMMER, OF HAMBURG, GERMANY.

" NCONS'IRUGTION' OR PREPARATION OF ROAD-SURFACES AND PAVEMENTS.

No Drawing.

' To all whom it may concern:

Be it known that I, KARL LUDWIG VALEN- TIN ZIMMER, manufacturer, asubject of the pebbles or otherstone material and asuit- German Emperor,residing at Hamburg,

Germany, have invented certain new and useful Improvements Relating tothe Construction or Preparation of Road-Surfaces.

and Pavements, of which the following is a specification.

This invention relates to the preparation of road surfaces and pavementsfrom gravel,

. able binding substance, with which the said material is coated.

Hitherto the tar, pitch or similar ma terial has been applied to theroad-metal or gravel by, purely mechanical means, the road-metal beingfirst dried, if necessary, and then intimately mixed with the previouslyheated binding substance, such as tar or pitch, in consequence of whichan undesirably large quantity of binding material had to be employed, inorder to produce a solid and even surface, and the binding substance wasliable to form patches or nests, which in hot weather become soft anddid not offer sufiicient resistance to the load, especially in the caseof heavy motor-traffic.

The present invention has for its object to provide a method of coatingthe roadmetal or gravel, whether dry or wet, uniformly with thenecessary quantity of binding material. For this purpose I first conyerttheoily or other water repellent binding substance, such as coal-tar,tar-oil, variouskinds of pitch, resin, asphalt-products,

- and .goudron, into a soluble or emulsified condition which may beefl'ected by known means, I then mix the solution or emulsion with thegravel, pebbles or other suitable road metal or stony particles and thenreconvert the solution or emulsion into a precipitate or coherentdeposit by treatment with acids, preferably dilute hydrochloric acid, orother suitable means. As such means are already'known, they need not beSpecification of Letters'latent.

Patented Nov. 28, 1911.

- Application filed April 23 1910. Serial No. 557,277.

described. In this manner each individual particle of-thepavementmaterial may be enveloped with the. binding substance in a state of finedivision, such as cannot be produced by purely mechanical means. Theusual waste of binding substance and unequal distribution of the same isthereby avoided.

The material produced as described is distributed in the usual manner onthe ,road or other base'to be covered and a uniform surface produced bymeans of a road roller or other known means, either immediately or afterthe material has been left exposed to the atmosphere for. a suitabletime.

What I claim is 1. The process for forming road surfaces and pavementsby means of stony particles and a waterrepellent binding substance,which consists in treating the stony particles with a solution oremulsion of the said binding substance to form a coating, subsequentlyprecipitating the said binding substance by chemical treatment, to forma coherent deposit, and finally finishing the road. surface mechanicallyin the usual manner,

substantially as described.

2. The process for forming road surface and pavements by means of stonyparticles and a water-repellent binding substance,

which consists in treating the stony particles I with a solution oremulsion of the'said binding substance to form a coating, subsequentlyprecipitating the said binding-substance by chemical treatment to formon the stony particles a'coherent deposit, then distributing the coatedparticles uniformly on the road base and finally finishing the surfacewith a roller, substantially as described. In testimony whereof I havehereunto set my hand in presence of two subscribing witnesses.

KARL LUDWIG VALENTIN ZIMMER. Witnesses:

Mosn MILLER,

ERNEST H. L. MUMMENHOFF.

